Several publications and patent documents are cited through the specification in order to describe the state of the art to which this invention pertains. Each of these citations is incorporated herein by reference as though set forth in full.
Insects are arthropods of the class Insecta. They have an adult stage characterized by a hard exoskeleton, 3 pairs of jointed legs, and a body segmented into head, thorax, and abdomen. Insects comprise the most diverse and numerous class of the animal kingdom and include numerous species of mosquitoes, grasshoppers, true bugs, flies, fleas, bees, wasps, ants, lice, moths, and beetles. The number of species is estimated at between 6 and 10 million, with more than a million species already described. Because, insects represent more than half of all known living organisms and potentially represent more than 90% of the differing life forms on Earth, human contact with insects is unavoidable. Exposure to biting or stinging insects or to their remains can range in severity from benign or barely noticeable to life threatening.
Container mosquitoes are prime public and veterinary health threats. Peridomestic containers, such as tire ruts, buckets, tarps, stock tanks, cans, discarded tires, and container-laden trash piles provide reservoirs that allow peridomestic mosquitoes to come in close contact with people, livestock, and companion animals. Such mosquitoes are difficult to control.
Some of the most effective means of controlling mosquito vectors of disease include those that are insecticidal. Insecticidal means include the use of adulticides as space sprays or indoor residual applications; insecticide-treated materials (ITMs), such as curtains or bed nets; and the application of larvicides to aquatic habitats. However, the primary challenges of realizing sufficient coverage of an insect population, especially at large or on spatially complex scales, remain, due to the uncertainty over the relative productivity of specific habitats, the consequent need to identify and treat potential sites, and local constraints on financial and human resources.
Conventional control methods focusing on treating or eliminating larval habitats generally are only efficient when individual larval sources are large and not numerous. However, these approaches are opposite to the actual distribution of container mosquito larval habitats, which tend to be small, plentiful, and reside in areas where host contact is maximal.
Autodissemination is a pest management method in which insects contaminated with a biological or chemical active ingredient transfer lethal doses horizontally or vertically to other insects by means of mating, oviposition, aggregation, and other behaviors. Autodissemination with insect vectored entomopathogen dissemination is well known. Autodissemination has also been used in the management of agricultural pests using dusting methods with powder formulations of insecticides. However, powder formulations are prone to loss over time due to grooming behavior of a number of insects, including mosquitoes, thus reducing efficacy.
Autodissemination has been used to disperse entomopathogens, such as entomopathogenic fungi, baculoviruses and nematodes (See, e.g., Soper, R. (1978). Autodissemination of entomopathogens: fungi. Future Strategies in Pest Management Systems (ed. by G. E. Allen, C M. Ignoffo & R. P. Jaques) pp. 63-65. Proceedings of the National Science Foundation. United States Department of Agriculture and the University of Florida Workshop on Microbial Control of Insect Pests, Gainesville, Fla.; Yu, Z. & Brown, G. C (1997). Autodissemination of a beet armyworm (Lepidoptera: Noctuidae) baculovirus under laboratory conditions. Journal of Economic Entomology, 90, 1187-1194; Klein, M. G. & Lacey, L. A. (1999) An attractant trap for autodissemination of entomopathogenic fungi into populations of the Japanese beetle Popillia japonica (Coleoptera: Scarabaeidae). Biocontrol Science and Technology, 9, 151-158; Lacey, L., Bettencourt, A., Garrett, F., Simoes N. & Gaugler, R. (1993) Factors influencing parasitism of adult Japanese beetles by entomopathogenic nematodes. Entomophaga, 38, 501-9; Autoinoculating device for contaminating insects with active agents. U.S. Pat. No. 5,452,540; Method and apparatus for autodissemination of insect pathogens. U.S. Pat. No. 5,359,807; Dowd, P. F. & Vega, F. E. (2003) Autodissemination of Beauveria bassiana by sap beetles (Coleoptera: Nitidulidae) to overwintering sites. Biocontrol Science and Technology, 13, 65-75).
Pyriproxyfen is a pyridine-based insect growth regulator. It is a mosquito larvicide that does not impair adult activity (Kawada et al., 1993), is active at extraordinarily low concentrations (Aedes aegypti L. LC50=0.023 ppb or 200× the activity of temephos), and females can serve as a vehicle for transferring insecticides to other larval habitats (Schlein & Pener, 1990). It generally is effective against a variety of arthropoda, possesses reduced risk, low resistance potential, and extraordinary mosquito efficacy. However, chemical insecticides, such as insect growth regulators have seen minimal use against insects, such as container mosquitoes, for a number of reasons, including inability of replication and killing of contaminated insects restricting effective dispersal.
The described invention addresses the above issues by providing a system, apparati and gel formulations for autodissemination of an insect-growth regulator for insect management. The described invention is inexpensive, biodegradable, requires no maintenance, offers extended toxicant activity, and maximizes topical transfer of the toxicant by manipulating gravid female search behavior. The gel formulations are easy to transfer to an insect body part, are difficult for insects to clean from an insect body part, are easy to transfer from an insect to target sites, have extended time of efficacy and poses minimum environmental hazard and health risk.